Clostridium difficile, an anaerobic spore forming Gram-positive bacteria, is the major cause of pseudomembraneous colitis and antibiotic associated diarrhea in humans and is one of the most widespread bacterium implicated in hospital acquired, nosocomial infections (see, for example, Wren, 2006, Future Microbiol; 1 (3):243-245). According to the Center for Disease Control (CDC), C. difficile is responsible for tens of thousands of cases of diarrhea and at least 5,000 deaths each year in the United States. The number of C. difficile infections doubled between 1993 and 2003, with the largest increase coming after 2000.
Individuals with a C. difficile-associated disease shed spores in the stool. C. difficile infections are frequently transmitted between hospitalized patients and the organism is often present on the hands of hospital personnel (see, for example, McFarland et al., 1989, N Engl J Med; 320:204-210). Patients infected with a C. difficile infection are isolated and precautions are taken to avoid outbreaks. Asymptomatic carriers can shed spores and need to be screened for isolation purposes (see, for example, Kyne et al., 2000, N Engl J Med; 342:390-397).
C. difficile spores are resistant to heat, drying, and cleaning agents and can survive up to seventy days on environmental surfaces, such as cart handles, bedrails, bedpans, toilets, bathing tubs, floors, furniture, linens, telephones, stethoscopes, thermometers, and remote controls. Thus, environmental surfaces are a ready source of infection. The thorough cleaning of patient's rooms during hospitalization is needed.
There is a clear need to monitor cleaning effectiveness and to verify that patient rooms and environmental surfaces are free of C. difficile spores. Currently, there are no easy to use, rapid methods for detecting C. difficile spores in environmental and patient samples. While kits (both immunoassay and molecular assays) are currently commercially available for the detection of C. difficile toxin, these kits do not detect C. difficile spores. Thus, there is a need for rapid and easy to use systems for the detection of C. difficile spores.